A manual of home-making

A pressure cooker cooks foot! in from one-third to one- fourth the usual length of time. Although its iuitial cost is some- what high, the amount of fuel that may be saved by its us*i during a year grc-atly decreases this cost. A steamer in which several kinds of food can be cooked at the same time over one burner saves fuel if the meal is planned to that end. Selection of wood. In general, the greater the drj' weight of a non-resinous wood, the more heat it will give out when burned. Woods having I I STOVES AND COOKERS 209 high fuel values are osage orange, lonist, hiekory, oak, apple; black birch, yellow liireh, hard maple, lj(x^*h, long-leaf pine, and cherr}% One cord of wood such as the aljove, weighing when dry about 3, .500 to 4,000 pounds^ is required to e<:|ual the heating value of one ton of coah Of other woods, such as ash, black wal- iiut» short-leaf pine, hemlock, red gum, sycamore, or soft maple, which weigh about 2,5fX) to 3,400 pounds a cord, it requires about a cord and a half to ecjual one ton of coal, while of wood guch as Norway pine, cypress, basswoocl, spruce and w^iite pine, two cords weighing when air dry 2,000 to 2,500 pounds each are required. The available heat value of a cord of wooti depends upon the extent to which it has been dritd. If the wood is green part of the heat is taken up in evaporating the water. Therefore the drier the wood, the greater is the available heat* A cord of wood occupies 128 cubic feet of space. If air spaces between the sticks are large, if the sticks are of small diameter, finely split, or twisted and knotty , or if the wood is loosely stacked, less wood is secured in a cord. If necessary to burn w^ood in a stove or furnace intendefl for coal, it may f>e done by covering the grate partly with sheet iron in which holes have been punchetl, or with fire bricks in order to rethice the draft. It this is not tlone the wood is wasted by being con- sumed too fast, producing a hot fire which may damage the fire-l>ox. Hickory is generally first choice among the non-resinous woods, liecause of the high fuel value to a unit volume of wood, even burning, and lasting quality. White oak is next, followed by black locust, luiri! maple, beech, l>irch, and '* white ash." The white pines have a relatively low heat value, but ignite readily and give out a quick hot Same. Kerosene stove. Kerosene h obtained by distilling crude petroleum which con- sists of a variety of infiammable liquids. The more volatile it is, the more brilliant the hght. Kerosene which can be heated Mi 210 A MANUAL OF HOME-MAKING to 140° I'\ witiioyt yielding a vapor, will not take fire even the container is l>roken and oil spilled.